Sunderland have enjoyed a strong start to life back in the second division of English football and currently sit fifth in the Championship table as they head into October.

Kristjaan Speakman dipped into the transfer market to bolster the squad in the summer by signing the likes of Ellis Simms, Daniel Ballard, and Edouard Michut.

However, some of the players who helped to secure promotion out of League One in 2021/22 have been among their top performers this term.

Ross Stewart, Alex Pritchard and Luke O'Nien are all in the top-seven players at the club in terms of average SofaScore ratings this season.

Sunderland's work in the market has been superb in recent seasons and O'Nien is one of the signings they played a blinder with when they snapped him up four years ago.

The Black Cats signed him from Wycombe for an undisclosed fee in the summer of 2018, with the midfielder - who signed a two-year deal - describing it as an "honour" to sign for the club. Transfermarkt valued him at £135k at the time of the move and that is a valuation he had held since August 2016.

The £5k-per-week battler was previously hailed by former manager Jack Ross. The Scottish boss said:

"He ticked a lot of boxes and then even when we did one-v-one stuff in training, he is awkward to get past, he is physical, competitive, and he doesn't like people going by him. He has been a revelation in that respect, and credit to him for how he has faced that challenge.

"When you play him in the middle of the pitch, he covers so much ground because you are involved all the time in the game."

O'Nien quickly established himself as a key player for Sunderland as he played 40 League One matches - including the play-offs - and chipped in with five goals and six assists.

In the following three seasons, he averaged a SofaScore rating of 7.02 or higher in the third tier as he amassed another 104 appearances in the division, which shows that he consistently delivered quality performances on the pitch for the club at that level.

His form led to Transfermarkt updating his valuation to £1.08m at the end of June 2022. This means that his value has rocketed by 700% since 2016 and this explains perfectly why Sunderland played a blinder by bringing him in back in 2018, as he has developed and improved during his time on Wearside whilst being a crucial member of the squad.

Since making the step up to the Championship, O'Nien has averaged a SofaScore rating of 6.92 across nine appearances - making 3.7 tackles and interceptions per game. Hopefully, he will now continue to prove his worth and increase his value as he continues to excel in the second tier for the Black Cats.